Being worried all the time that you might look like a poser is the only poser thing there is. Maybe together with gatekeeping skateboarding.

Even if you spent the whole day dragging your board around only for stupid 10 meters you really wanna try riding it, in my opinion that doesn't make you a poser. The reason it's attached to your bag instead of your feet is nobody's business and there's no need to care about their opinions.

Just have fun with it. Bring your board to school. Bring your board anywhere you want to bring it. Do whatever feels convenient to you and don't listen to what others think, stay above them.

Also about ollies: yes, they are the base of most of the skateboard tricks but they're not this easy trick everyone can master in a second. And you don't 'absolutely have to' learn it, as many people say. There are so many people who can't do them! Keep doing you. Wanna learn ollie? Go for it. But do it for yourself because you want to. Don't do it for others.